Expansion boring-bar.



' E. P. MERTES.

EXPANSION BORING BAR. APPLICATION FlLED FEB. 19. 19.!2.

Patented July 17, 1917.

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EDWIN PHILLIP MERTES, OF ST. LOUIS, MISSOURI XPANSION BORING-BAR.

' :Zcation filed February 19, 1917. Serial No. 149,611.

To all whom it may concern: 7

Be it known that I, EDWIN 'PHILLIP Mnn'rns, a citizen ofthe UnitedStates, and

resident of- St. Louis, Missouri, have'invented certain new and usefulImprovements in Expansion Boring-Bars, of which the following is aspecification contaming a full, clear, and exact description, referenceboring bar', cutters of varying sizes must be provided in order to boreholes of difierentsizes. This requires a set of cutters'of largenumbers, at increased cost, and also necessitates the entire removal ofa particu lar size cutter to accommodate the cutter to a hole ofdifferent dimensions with a consequent loss of time.

With my device but one set of cutters is necessary for any size hole,the changing to different sizes being accomplished by an adjustment ofthe cutters. Any number of cutters may be used with my device. I haveshown four, but the tool can be designed for any greater or lessernumber. I do not desire to be limited to four, the number I have takenas being illustrative of any number of blades.

My tool is capable of boring or reaming holes with extreme accuracyowing to the delicacy of adjustment made possible by my structure; itcan be made to fit any style tool post, or spindle on any lathe, boringmill, radial drill, etc. it can bore square to the shoulder of a pieceof work, without interference from set screws or look screws containedin the bar; such set screw preventing this in a large number oftheboring tools now in the art.

With the above and other objects in View,

, my invention has relation to certain novel features of constructionand operation, examples of which aredescribed in the followingspecification and illustrated in the accompanying drawing in which-Figure 1 is a sectional longitudinal elevation of my device.

Fig. 2isan end view of my device.

Fig. 3 is a cross section on the line 3-3 of Fig. 1. 4

' Fig. 4 is a cross section on the line 44 of Fig. 1-

I Fig.5 is a segmental c oss-section on the line 55 of Fig. 2.

ters.

Fig. 7 is cross section on the line 77 of Fig. 6. v

Referring to these figures, numeral 8 designates a portion of a shank bywhich my tool is securedto a source of rotation such as a lathe, boringmill, etc. To the shank 8, the 'tool body 9, is secured by means of thethreads 10. In the tool body 9 is formed a cylindrical aperture ofcircular section 11. In aperture 11 is located the worm gear 12, havingformed on its one extremity the head 13, with a wrench hole 14, formedon its top. The shaft end of the worm gear Specification of LettersPatent. Patented July 1'3, 1911'?- i Fig. 6 is an elevation of one ofthe cut.- 1

12, is countersunk with a threaded hole 14; 15 designates a bolt with ahead 16' and the threaded shaft 17. Numeral 18' designates a shoulder onthe tool body 9 in the aperture 11; 19 likewise represents a secondshoulder on the tool body 9.

When the worm gear is placed in the position shown in Figs. 1 and 2, thehead rests on .the shoulder 19. The bolt 15 is screwed into the threadedhole 14 until the head 16 rests on the shoulder 18. By these means theworm gear 12 is rotatively secured in the cylindrical aperture 11; 20des ignates a casting consisting of the Worm wheel 21, the cam wheel 22and the project ing studs 23 and 24 respectively, all'made integral. 25designates a circular plate having the shoulder 26 which rests againstthe offset 27 of the tool body 9 and flush with the end of the shank 8as shown in Fig. 1. In the center of plate 25 is punched the hole 28. Inthe tool body, in the portion designated 29 is formed the hole 30. Thecasting 20 is positioned as shown in Fig. 1 so that stud 23 is rotatablysecured in hole 28 of plate 25 and stud 24 is rotatably secured in hole30 of the tool body portion 29. The

spectively. The edge 36, it is to be noted is tapered toward the edge34.

To demonstrate the positioning of the cutter shown in Eig. 6, in Fig. 1I have designated the remainder edges 37-38 and 39 respectively. Thecutters are arranged as shown in Fig. 4: in slots 40. It will beobserved when the cam wheel 22 is rotated in an anticlockwise direction,the blades will be forced radially outward. The curves of the cams thatI have shown are circles with their centers non-coincident with thecenter of the casting. It will be seen by observing Fig. 4 that thedisplacement of any cutter radially equals the length of the facedesignated by the numeral 41, z. 0., the diametrical displacement of twodiametrically opposed blades will be twice the length ofthe face 41,this distance then represents the "ran'ge in the diameter of hole thatcan bebored with the cutter. The notch 42 on the cutter represents themeans I have devised for preventing lateral displacement of the cutter.For the purpose of holding a cutter in "a predetermined position I haveformed an angular depression 43 in one of its sides and an opening 44 inthe tool body 9 into which a bolt 45 is rotatively secured by thethreads 46.

What I claim and mean to secure by Letters Patent is:

In a device of the character described, in combination with a tool body,and means for rotating, said device, said tool .body socured to saidlast named means, a set of cutter blades, a worm' gear, and a cam wheel,said worm gear and said cam wheel rotatively secured to said body, thecam face of said cam wheel in frictional contact with a dull edge ofeach cutter blade, means for rotating said worm gear so as to produceradial movement of said blades, means for securing adjustablv saidblades to the tool .body in determined positions, consistingof a boltpassing through the tool body and into depressions in said blades,substantially as and for the purposes described.

In testimony whereof, I have signed my name to this specification, inpresence of two subscribing witnesses.

EDWIN PHILLIP MERTES.

V. Witnesses? LEONA .PRIOE, HARRY- V. Love.

